The Japan-to-Congress story
Japan has produced 2 naturalized citizens who went on to serve in the US Congress — 1 in the House of Representatives and 1 in the Senate. 2 are currently serving, while 0 have completed their congressional careers. The first of them entered Congress in 1997, during the late twentieth century; the most recent arrived in 2013, during the modern Congress. Collectively they represented 2 different US states — a reminder that naturalized-citizen members of Congress come from every region of the country, not a single immigrant gateway.
Japan reserves the ballot for its own citizens: non-native-born residents cannot vote in any election there, no matter how long they have lived in the country. Specifically: Only Japanese citizens can vote. Dual citizenship is prohibited. Non-citizens have no voting rights at any level.
Every Japan-born member tracked here has served as Democrats. That produces a striking asymmetry with the United States, which not only naturalized this member but then elected them to help write federal law. A naturalized American who returned to Japan would have no such political voice there. Across the full history of the US Congress, Japan ranks 14th of 38 tracked birth countries, accounting for 2 naturalized-citizen lawmakers.
Put plainly: a person born in Japan can be entrusted by American voters with a seat in the US Congress, writing federal law for hundreds of millions of people. Yet the same person, if they returned to Japan, would be barred from casting even a single ballot there. That is the contrast this tracker exists to surface.